The principal active peptide in honey bee venom is melittin.
Melittin is a 26-amino-acid peptide and makes up roughly 40–60% of the dry weight of honeybee venom. It is the venom’s major pain-producing component, helping explain the immediate burning sensation after a sting. Its amphipathic structure allows it to interact with and disrupt cell membranes.
Melittin forms pores in membranes, damages red blood cells, and promotes inflammatory signaling. Bee venom is not a single toxin, however: phospholipase A2, apamin, hyaluronidase, tertiapin, secapin, and other compounds contribute to its effects. That is why “bee venom” and “melittin” are not interchangeable terms.
A common mix-up is apamin, another famous honeybee-venom peptide. Apamin is a neurotoxin that affects potassium channels, whereas melittin is the dominant pain- and membrane-damaging component. The honeybee’s scientific name is Apis mellifera, and its venom is also called apitoxin.